Cal Baier-Anderson, PhD, is a Health Scientist.
In our critique of EPA’s Chemical Assessment and Management Program (ChAMP), we have pointed out that, despite its limitations, there is value in the hazard data that EPA is collecting and analyzing. How so?
First, we recommend that the hazard profile of the chemical be the main factor in determining a chemical’s priority. One of the reasons for this is the hazard properties are intrinsic to the chemical – they basically do not change even when the chemical is used in different ways. Given the difficulty in knowing or anticipating all of the different applications for a chemical, the hazard data and characterization are extremely useful to have in hand for current and potential users of the chemical.
While EPA has yet to even consider the possibility, the screening-level hazard data and hazard characterizations it is developing can also help inform safer substitution. Each ingredient in a product formulation has a specific function, for example, to reduce surface tension (surfactants), dissolve materials (solvents), reduce water hardness (chelating agents) or provide or mask a scent (fragrances). The functional class is typically related to chemical and physical properties.
By comparing the hazard profiles of chemicals within a functional class, the chemicals with lower hazard profiles can be preferentially selected. This is the basic approach taken by EPA’s own Design for the Environment Program, which works with companies to screen product ingredients, identify chemicals of concern and identify and promote use of safer substitutes.
So how could ChAMP be used to leverage green chemistry and facilitate safer substitution? By tagging each chemical evaluated under ChAMP with its functional class and identifying its applications (to the extent they are known). It should then be feasible to group the ChAMP chemicals by functional class to facilitate comparison of their hazard profiles. This information could be invaluable to companies interested in selecting safer chemical substitutes to perform a given function.
Functional class should not be confused with chemical class. For example, within the solvent functional class, there are chemicals from many different chemical classes, including: alcohols, esters, ethylene glycol ethers (EGEs) and propylene glycol ethers (PGEs). While chemicals within a given chemical class may often have similar hazard properties, there will often be significant differences in hazard between the chemical classes that serve a given function.
This may not always be the case, of course. For some functional classes and some endpoints, there may be very little difference in hazard among members because of the function that they perform. For example, surfactants typically demonstrate aquatic toxicity because they are, by definition, surface-active. In such cases, the entire functional class – or the underlying functionality – could be the focus of a “green chemistry challenge program” that would fund research into or otherwise seek to spur development of safer alternatives.
What would be needed to “green” ChAMP along these lines? The following would be a start:
- Convert the hazard data collected and analyzed in ChAMP into a sortable, searchable spreadsheet or other database that allows side-by-side comparisons.
- Identify known applications of each ChAMP chemical.
- Add functional class tags to each chemical.
For item # 1, tables summarizing the hazard data are already included in the hazard characterizations supporting each chemical or chemical category evaluated. These tables simply need to be transferred into a searchable, online database.
For item #2, applications can be gleaned from a variety of sources, including information submitted by industry under the Inventory Update Rule (IUR), the Hazardous Substances Data Bank and the National Library of Medicine’s Household Products Database. The information available via these resources is often extremely limited and out-of-date. Over time, we can expect our understanding of how chemicals are used to get better, for example as a result of data submitted under the European Union’s REACH Regulation and hopefully, once the Toxic Substances Control Act is reformed.
(As is clear from our earlier posts on ChAMP, EDF has been very critical of EPA’s heavy reliance on incomplete, unverified and confidential IUR information to draw conclusions about exposure and risk of HPV chemicals. What I’m proposing here is a far more appropriate use of the IUR data, one much less sensitive to its deficiencies: to glean any available functional use information solely for the purpose of identifying chemicals sharing a function.)
For item #3, a field can be created in the online database for functional class information. As with information on applications, functional class designations can also be difficult to obtain, but are likely to become more available in the future.
One source of both functional class and application information to consider is a subscription-based web service such as Chemidex, which compiles this type of information to facilitate information exchange among formulators. The advantage of accessing this type of informational database is that the information comes directly from companies making products, rather than chemical manufacturers. Still, challenges remain; for example, the listed products include mixtures, some with proprietary formulations.
Another model for this type of database is CleanGredients, which also provides information for formulators on general product and regulatory information, physical-chemical properties and human and environmental health data.
There are three needed components to forge this linkage:
Hazard Data + Functional Use + Application
Efforts like those of Chemidex and CleanGredients are beginning to provide tools able to facilitate functional use approaches to comparison and selection among chemical (and non-chemical) alternatives, albeit on a small scale and within limited categories. With the hazard data it’s collected and is now assessing under ChAMP, EPA could begin to do so on a larger scale.
In conclusion, one means of “greening” ChAMP would be to link the hazard data EPA is evaluating with meaningful functional use information. Such an approach can start to challenge the assumption that continued production and use of high-production-volume chemicals with undesirable hazard traits is the only option.